Lemonergy · Studio block

Thermal radiation

Effective two-body Stefan-Boltzmann exchange at absolute temperatures

Implementation ID: thermal-radiation
Reviewed: 2026-10-27

Behavior

Conserving component solved simultaneously with the connected network. Effective two-body Stefan-Boltzmann exchange at absolute temperatures

Interface

Original Lemonergy interface view. Lines identify ports; they are not a completed simulation circuit.

Ports and observed outputs
Name	Direction	Unit	Meaning
`a`	terminal	K; W	thermal conserving connection; absolute temperature with balanced heat flow.
`b`	terminal	K; W	thermal conserving connection; absolute temperature with balanced heat flow.
`heatFlow`	output	W	Recorded heat flow measurement from the conserving simulation.
`temperature`	output	K	Recorded temperature measurement from the conserving simulation.
`temperatureDifference`	output	K	Recorded temperatureDifference measurement from the conserving simulation.

Parameters

Defaults are initial model values. Select values for your own model and operating conditions.

Configuration fields
Parameter	Unit	Default	Meaning and limits
Effective emissivity `emissivity`	fraction	0.8	Effective surface emissivity used in radiative heat exchange. Minimum 0; Maximum 1
Effective view factor `viewFactor`	fraction	1	Fraction of radiative exchange represented between the two modeled surfaces. Minimum 0; Maximum 1
Exchange area `areaM2`	m2	0.02	Area used by the declared heat-transfer or parallel-plate field equation. Minimum 1e-12; Maximum 1000000

Equations and rules

Q̇a→b = ε F σ A (Ta⁴ − Tb⁴)

Worked example

Thermal radiation worked example

Editable first-party network. hot-boundary: differenceK=320; cold-boundary: differenceK=300. Checks below were verified in the native execution engine.

Open Studio example after release →

Numerical checks for the bundled synthetic example
Output	Time (s)	Expected value	Unit	Absolute tolerance
heatFlow `target/heatFlow`	1	`2.1645044`	W	2.1645043958220922e-06
temperature `target/temperature`	1	`320`	K	0.00031999999999999997
temperatureDifference `target/temperatureDifference`	1	`20`	K	1.9999999999999998e-05

Use in a workflow

Thermal radiation worked example

Effective two-body Stefan-Boltzmann exchange at absolute temperatures

Thermal radiation: Conserving component solved simultaneously with the connected network. Effective two-body Stefan-Boltzmann exchange at absolute temperatures
- Use the block reference for settings and connections.
- Implementation tested locally; public release pending.

Open Studio example after release

Connected concepts

Limits and interpretation

Effective two-body Stefan-Boltzmann exchange at absolute temperatures
Demonstration parameters are not calibrated hardware data. Singular or incompatible ideal constraints and unsupported state ranges stop the run.

Scientific and mathematical references

These sources explain the scientific and mathematical background. The behavior, interface and limits above define the Lemonergy implementation; a citation does not imply every model option in the source is implemented.

University Physics Volume 2, §1.6: Mechanisms of Heat Transfer
OpenStax, Rice University
Technical reference · Conduction, convection, radiation and thermal resistance.
Stefan–Boltzmann constant, 2022 CODATA
NIST
Technical reference · Underlying physical law or reduced-model basis; Lemonergy implementation choices and limits are documented separately.

Implementation sources

This reference follows the public interface and locally verified numerical checks for an upcoming release.

Contract: Lemonergy Studio public contract · Verification record: verification-2026-10-27

docs/glossary/native-block-verification.json

This implementation and its workflow uses (JSON) · Knowledge graph (JSON-LD)